EN
The duration of reproductive capacity of 166 boars (68 of the Great White Polish, 64 Polish and 14 Duroc) kept in individual boxes with a slatted floor and a shift on an industrialized farm was examined in 1984-1991. A mean time of reproductive capacity of boars was 508 days. Only every fourth boar was used for reproduction for more than 2 years. Factors such as time of birth, origin from primiparous or multiparous sows, rate of growth and selection index did not affect significantly the duration of the reproductive capacity of boars.